Online Event
September 01-03, 2022 | Online Event
GPMB 2022

Exploring multitrophic interactions for agricultural sustainability

Diego M Magalhaes, Speaker at plant science conferences
University of São Paulo, Brazil
Title : Exploring multitrophic interactions for agricultural sustainability


Soil microorganisms with growth-promoting activities in plants, such as rhizobacteria, can improve plant health in many ways. These beneficial organisms may confer to plants broad-spectrum resistance by modifying their physiological status and affecting their interactions with herbivores, natural enemies, and pollinators. I will present results on the interactions of the plant growth-promoting rhizobacterium (PGPR) Bacillus amyloliquefaciens with tomato plants, Solanum lycopersicum L., the specialist herbivore Tuta absoluta (Meyrick), the predator Macrolophus basicornis (Stål), and the stingless bee Melipona quadrifasciata Lep. through a combination of chemical and behavioural approaches. Our results showed that rhizobacterial colonization of tomato roots increased the endogenous level of jasmonic acid compared to control plants (mock). Volatile analysis revealed that PGPR-treated plants also increased their emission of several terpenoid compounds. Total floral volatiles was also increased in PGPR-treated plants. Moreover, rhizobacterial inoculation significantly affected plant biomass, increasing root, shoot and flower dry weight, but did not affect the germination rate. Tomato plants were more resistant to T. absoluta when inoculated with the rhizobacterium. The rhizobacterial treatment resulted in decreased larval and pupal weight compared to mock plants. Tuta absoluta laid significantly fewer eggs on PGPR-treated plants compared to untreated plants. In two-choice oviposition experiments, a significantly higher number of eggs were laid on untreated plants compared to PGPR-treated plants. In terms of indirect defence, PGPR-treated plants were more attractive to M. basicornis than untreated plants, however, when the predators were given a choice between PGPR-treated and T. absoluta-damaged plants, they preferred the latter. Pollinators also showed a clear preference for flower volatiles from PRGPR-treated plants. Overall, our results indicate that B. amyloliquefaciens modulates tomato defence against T. absoluta by modifying plant chemistry and enhancing the attraction of predators and pollinators.



Diego began his studies at the Catholic University of Brasília, Brazil, from which he holds a BSc in Biological Sciences. He completed an MSc in Ecology and a PhD in Zoology from the University of Brasília in 2016, researching plant-insect interactions and chemical ecology. Shortly thereafter, he joined the Brazilian Agricultural Research Corporation (EMBRAPA) and then Rothamsted Research, UK. He is now working for the University of São Paulo, Brazil, and his research is centred on multitrophic interactions among plants, insects and microorganisms, chemical ecology and sustainable agriculture.